How We Measure Handling

Best-Handling Car For Less Than $40,000.

Cayman Dynamics, C/D’s expert witness for special investigations, assembled an $80,000 instrument package to assess each test car’s response to controlled steering inputs. The sensor array consisted of four infrared height-measuring devices (one per corner); a strap-on steering wheel (to report steering angle, steering effort, and the steering-input rate); and a six-axis inertial sensor (signaling roll, pitch, and yaw rates plus lateral, longitudinal, and vertical accelerations). A VBox III data logger (sampling 100 times per second) recorded all sensor signals in sync with vehicle speed and position information while each car gradually accelerated from rest to the adhesion limit on a 300-foot-diameter skidpad. Reducing the data yielded the steering angle, steering effort, and body-roll-versus-lateral-acceleration curves shown here.

To quantify damping, we added a new procedure to this year’s best-handling competition. It examines how each car reacts to rapid steering inputs. Ideally, a vehicle’s springs, dampers, and anti-roll bars quickly check the roll, pitch, and yaw motion of the car following a disturbance from steering, acceleration, braking, bumps, or any combination of the four inputs. The general term used to describe how well the suspension handles such disturbances is body control. To measure car-to-car damping differences, Cayman drove each test car at 70 mph while applying sinusoidal steering inputs of varying magnitude and frequency. The dynamic responses recorded by the instruments were then analyzed to determine the relative roll-damping figures reported here and in our results chart.

The Mustang GT, at the low end of the scale, was assigned an index figure of 1.00, while the Mitsubishi Evo, with 54-percent greater damping, has a figure of 1.54. The roll-damping indexes of the four other test cars fall between these two extremes.